Academic literature on the topic 'Glaciers – Tanggula Mountains (China)'

Air temperature and precipitation data have been obtained from the Geladandong region at the headwaters of the Yangtze River. At the equilibrium line altitude of the glaciers, mean annual and summer air temperatures are –10 to –12.0°C and 1.0 to –1.0°C, respectively. Accumulation on the glaciers on the south side of the Tanggula mountains depends mainly on water vapour transported from the south and southeast. The moisture source for the glaciers on the north side is from the east. Precipitation increases with altitude in the glaciated areas. An estimated annual accumulation in the firn areas is about 400 to 600 mm of water equivalent. The Geladandon region has a cold, dry climate and the glaciers in the region can be classified as continental. The present climatic conditions result in a negative mass budget for most glaciers.

Air temperature and precipitation data have been obtained from the Geladandong region at the headwaters of the Yangtze River. At the equilibrium line altitude of the glaciers, mean annual and summer air temperatures are –10 to –12.0°C and 1.0 to –1.0°C, respectively. Accumulation on the glaciers on the south side of the Tanggula mountains depends mainly on water vapour transported from the south and southeast. The moisture source for the glaciers on the north side is from the east. Precipitation increases with altitude in the glaciated areas. An estimated annual accumulation in the firn areas is about 400 to 600 mm of water equivalent. The Geladandon region has a cold, dry climate and the glaciers in the region can be classified as continental. The present climatic conditions result in a negative mass budget for most glaciers.

In the past decade the interest of many scientists worldwide has been attracted to the central Asian area of China. A number of gaps in scientific knowledge have been closed, and many significant discoveries have been made.The most important achievement is the ice-core research by the Sino-American Joint Expedition to the Dunde Ice Cap, Qilian mountains, that established a record of ten thousand years of climatic and environmental change. In addition, in cooperation with scientists from Japan, Switzerland and the Soviet Union, studies have been carried out focusing on glacier mass balance, heat balance, the mechanism and formation of glacial runoff, and high mountain climates. This work has been done in the Tien Shan, west Kunlun, Tanggula, Nyaingentanglha and Gongga mountains.In addition, through joint efforts of scientists from China, Nepal and Canada, important advances have also been made in studies of glacier lake outburst floods and debris flows in the Karakoram and the Himalayas, and in mountainous areas in southeastern Tibet.The glaciers in central Asia will continue to be an important research area for glaciologists from all over the world in the coming decade.

In the past decade the interest of many scientists worldwide has been attracted to the central Asian area of China. A number of gaps in scientific knowledge have been closed, and many significant discoveries have been made.The most important achievement is the ice-core research by the Sino-American Joint Expedition to the Dunde Ice Cap, Qilian mountains, that established a record of ten thousand years of climatic and environmental change. In addition, in cooperation with scientists from Japan, Switzerland and the Soviet Union, studies have been carried out focusing on glacier mass balance, heat balance, the mechanism and formation of glacial runoff, and high mountain climates. This work has been done in the Tien Shan, west Kunlun, Tanggula, Nyaingentanglha and Gongga mountains.In addition, through joint efforts of scientists from China, Nepal and Canada, important advances have also been made in studies of glacier lake outburst floods and debris flows in the Karakoram and the Himalayas, and in mountainous areas in southeastern Tibet.The glaciers in central Asia will continue to be an important research area for glaciologists from all over the world in the coming decade.

The response of lake-terminating glaciers to climate change is complex, and their rapid changes are often closely linked to glacial-lake outburst floods. However, the eastern Tanggula Mountains, which are the only area where lake-terminating glaciers are found within the Tibetan Plateau, have received little attention to date. In this study, to address this gap, we generated updated glacier boundaries and estimated the interdecadal area changes for 2000–2020 based on the interpretation of Landsat-5/8 and Sentinel-2 images. In addition, based on the method of digital elevation model (DEM) differencing, we quantified the changes in glacier thickness and mass balance using TanDEM-X radar data and SRTM DEM over almost the same periods. The final results show that the glaciers in the eastern Tanggula Mountains, as a whole, have experienced accelerated area shrinkage (with a rate of area loss increasing from −0.34 ± 0.83 km2 a−1 to −0.93 ± 0.81 km2 a−1 for 2000–2013 and 2013–2020, respectively) and accelerated ice thinning (changing from −0.19 ± 0.05 m a−1 and −0.53 ± 0.08 m a−1 for 2000−2012 and 2012–2020, respectively). Furthermore, the region-wide glacier mass balance was −0.16 ± 0.04 m w.e. a−1 and −0.45 ± 0.07 m w.e. a−1 for these two sub-periods, corresponding to a 1.8 times acceleration of mass loss rate. The average mass balance during 2000–2020 was −0.23 ± 0.04 m w.e. a−1, which is equivalent to a rate of mass loss of −0.04 Gt a−1. More specifically, within the region, the lake-terminating glaciers have exhibited more significant acceleration of area loss and mass loss, compared to the land-terminating glaciers. However, interestingly, the average thinning rate of the lake-terminating glaciers is always lower than that of the land-terminating glaciers over all study periods, which is in contrast with previous findings in other high mountain areas (e.g., the Himalaya Mountains). Field study and proglacial lakes monitoring suggest that the local topography plays a vital role in the evolution of the glacial lakes in this region, which further affects the glacier changes. Furthermore, the present status of the glacier changes in this region can be attributed to the long-term increase in air temperature. Our findings provide a comprehensive overview of the current state of glacier changes across the eastern Tanggula Mountains and will help to improve the understanding of the heterogeneous response of glaciers to climate change.

AbstractClimatic changes in the Qinghai-Xizang Plateau of China were studied by analyzing the composition of peat and layers of sand and gravel distributed along the southern slopes of Nianqing-Tanggula and Gangdise Mountains, cross sections of deposits near a number of interior lakes in Xizang, past glacial variations on the southern slope of Nianqing-Tanggula Mountain, and landform changes south of the Yaluzangbu River. Such geologic evidence suggests a division of five climatic periods since the beginning of the Holocene: (1) The Wumadung interval, 10,000–7500 yr B.P., slightly cold and dry; (2) Qilongduo interval, 7500-3000 yr B.P., warm and moist; (3) the mid-Neoglacial period, 3000-1500 yr B.P., cold, except between 2500 and 200 yr B.P. when it was warmer; (4) the Dawelong interval, 1500-300 yr B.P., mild; and (5) the Little Ice Age, 300-0 yr B.P., cold. These changes progressed in a similar but not identical pattern as those in the northeastern part of China and in the northern region of Europe.

Glaciers in the Qilian Mountains are important sources of fresh-water for sustainable development in the Hexi Corridor in the arid northwest China. Over the last few decades, glaciers have generally shrunk across the globe due to climate warming. In order to understand the current state of glaciers in the Qilian Mountains, we compiled a new inventory of glaciers in the region using Landsat Operational Land Imager (OLI) images acquired in 2015, and identified 2748 glaciers that covered an area of 1539.30 ± 49.50 km2 with an ice volume of 81.69 ± 7.40 km3, among which the Shule River basin occupied the largest portion of glaciers (24.8% in number, 32.3% in area, and 35.6% in ice volume). In comparison to previous inventories, glacier area was found to shrink by 396.89 km2 (20.5%) in total, and 446 glaciers with an area of 44.79 km2 disappeared over the period from the 1960s to 2015. This situation was primarily caused by the increase in air temperature, and also related with the size of glacier and some local topographic parameters. In addition, the change of glaciers in the Qilian Mountains showed a distinct spatial pattern, i.e., their shrinking rate was large in the east and small in the west.

AbstractGlaciers in China are primarily located in the Tibetan Plateau (TP) and surrounding high mountains. The Chinese Glacier Inventory indicates that there are 46 377 glaciers in western China. Meteorological records indicate that air temperature in western China has risen by 0.2˚C per decade since 1951, and 1998 was the warmest year; precipitation in the region increased by 5–10% per decade from 1953 to 1997. Using remote-sensing and Geographic Information System methods, we have monitored the changes in >5000 glaciers over the past 50 years. We conclude that >80% of glaciers in western China have retreated, losing 4.5% of their combined areal coverage, although some glaciers have advanced. In addition, regional differences characterize glacier changes over the past few decades. For example, glaciers in the central and northwestern TP were relatively stable, while glaciers in the mountains surrounding the TP experienced extensive wastage. Mass-balance variations for some glaciers show accelerated ice shrinkage in the last two decades.

Glaciers over the Tibetan Plateau have experienced accelerated depletion in the last few decades due primarily to the global warming. The freshwater drained into brackish lakes is also observed by optical remote sensing and altimetry satellites. However, the actual water storage change is difficult to be quantified since the altimetry or remote sensing only provide data in limited dimensions. The altimetry data give an elevation change of surface while the remote sensing images provide an extent variation in horizontal plane. Hence a data set used to describe the volume change is needed to measure the exact mass transition in a time span. In this study, we utilize GRACE gravimetry mission to quantify the total column mass change in the central Tibetan Plateau, especially focused on the lakes near Tanggula Mountains. By removing these factors, the freshwater storage change of glacier system at study area can be potentially isolated.